Installations for sterilizing articles, in particular trays for food products, are known, such an installation comprising an enclosure with a conveyor passing therethrough having the articles disposed thereon, and an electron bombardment device disposed above the conveyor for treating the articles with vertical radiation. Such installations are satisfactory for articles of small height, and they enable articles to be sterilized while using low-energy electron radiation.
In contrast, when the articles are of considerable height and/or thickness, for example when the articles are bottles, it is necessary to increase the electron bombardment energy very considerably so that the electron radiation can reach the bottoms of the bottles after passing through their walls and still have enough energy to ensure sterilization at the bottoms of the receptacles. With bottles, the electron bombardment energy also needs to be increased because the neck of the bottle absorbs a fraction of the electron radiation energy before it reaches the bottom of the bottle. High-power electron bombardment then raises the problem of deteriorating the portions of the article that are closest to the bombardment device, in particular the neck when the article is a bottle.
It is also known from document U.S. Pat. No. 4,944,132 a sterilization installation comprising two electron bombardment members disposed at different orientations relative to the articles that are to be sterilized but both emitting a horizontal radiation over receptacles extending vertically. The bottom of a bottle would not be satisfactorily sterilized with an installation according to this document.
In addition, high-power electron bombardment runs the risk of propagating outside the enclosure and thus of constituting a danger for operators moving around the installation.